Antistatic laminate filament and fabric prepared therefrom

ABSTRACT

Disclosed is a fabric which avoids the accumulation of high concentrations of static electricity while presenting no appreciable electrocution hazard. The fabric comprises novel continuous laminate filaments each of which has (A) at least one polymeric ply bonded to (B) a ply made of electrically conductive material and having at least one discontinuity along its length.

United States Patent 1191 Lowry et al.

1 1 Oct.1, 1974 1 ANTISTATIC LAMINATE FILAMENT AND FABRIC PREPAREDTHEREFROM [75] Inventors: Charles Everett Lowry; William J.

Gilbertson; James A. Gusack, all of Williamsburg, Va.

[73] Assignee: Dow Badische Company,

Williamsburg, Va.

[22] Filed: Aug. 25, 1971 21 Appl.No.:174,743

Related US. Application Data [63] Continuation-in-partof Ser. No.93,194, Nov. 27,

1970, abandoned.

52 us. c1 .,161/65,161/67,161/146, 161/172, 161/214, 161/403 51 1111. C1D03d 27/00 [58] Field Of Search 161/65, 67, 146, 172, 175, 161/178, 214

[56] References Cited UNITED STATES PATENTS 3,069,746 12/1962 Scharf161/220 3,361,616 l/1968 Scharf 161/214 3,379,000 4/1968 Wcbber et a1.161/172 3,582,444 6/1971 Ngo ct a1. 161/175 3,582,445 6/1971Okushaski.... 3,678,675 7/1972 Klein 3,690,057 9/1972 Norris 57/157 ASPrimary Examiner-William J. Van Balen Attorney, Agent, or Firm-George F.Helfrich [57] v 7 ABSTRACT Disclosed is a fabric which avoids theaccumulation of high concentrations of static electricity whilepresenting no appreciable electrocution hazard. The fabric comprisesnovel continuous laminate filaments each of which has (A) at least onepolymeric ply bonded to (B) a ply made of electrically conductivematerial and having at least one discontinuity along its length.

7 Claims, 4 Drawing Figures S R O T N E V W WIL LIAM J. GI LBE RTSONJAMES A. GUSACK THEIR ATTORNEY PATENTED 0m 1 974 Y m L T T E R E. V E SE L R A H C O O W CROSS REFERENCE TO OTHER APPLICATION This applicationis a Continuation-in-Part of our copending application Ser. No. 93,194filed Nov. 27, 1970 now abandoned.

BACKGROUND OF THE INVENTION 1. Field of the Invention The presentinvention relates to textiles in general, and more specifically tofabrics'having excellent antit of static electricity, while presentingno appreciable static characteristics, which fabrics contain laminatefilaments.

2. Prior Art The accumulation of static electricity as a result of theutilization of fabrics is a phenomenon which has commanded the attentionof the textile industry for some time. The presence of static is a causenot only of annoyance (e.g., items' of apparel cling to the body and areattracted to other garments; fine particles of lint and dust areattracted to upholstery fabrics, increasing the frequency of requiredcleaning; one experiences a jolt or shock upon touching a metal doorknobafter walking across a carpet), but also of danger (e.g., the dischargeof static electricity can result in sparks capable of igniting flammablemixtures such as ether/air, which are commonly found in hospitals,especially in operating rooms). All of these effects are accentuated inatmospheres of low relative humidity.

f the many proposals for preventing the undesirable buildup of staticelectricity, the most satisfactory, with respect to their efficiency andpermanence. appear to be those which comprehend the utilization offibers possessing electrical conductivity (e.g., metal fibers, fiberscoated with electrically conductive material, or metallic laminatefilaments) in combination with common natural and man-made fibers toproduce a woven, knitted, netted, tufted, or otherwise fabricatedstructure, which readily dissipates the static charges as they aregenerated. Some of the more noteworthy of these methods and structuresmay be found in US. Pat. Nos. 2,129,504; 2,714,569; 3,069,746;3,288,175; 3,582,444; and 3,582,445; and in Webber, Metal Fibers. ModernTextiles Magazine, May, I966, pp. 72-75.

Notwithstanding the efficacy of these expedients in the dissipation ofstatic, they are found lacking in one most important aspect; viz., thereis no comprehension of, and therefore no specified provision toeliminate, the electrocution hazard which could result from theemployment of such electrically conductive material. Specifically, thecontinuum of electrically conductive material, which affords theconductivity necessary for dissipation of any static charges which mayhave been generated in the fabrics, could also result in harm to thosetouching these fabrics in the event of accidental contact of suchfabrics with a source of essentially unlimited electrical current, as isavailable from an ordinary electrical outlet, or an electrical applianceshortcircuited by insulation failure.

SUMMARY OF THE INVENTION Accordingly, it is a primary object of thisinvention to provide a fabric which efficiently and permanently avoidsthe accumulation of undesirable concentrations electrocution hazard. Itis another primary object of this invention to provide novel laminatefilaments which find utility in the preparation of these novel fabrics.

In accordance with this invention, these advantages are achieved, andthe problems inherent in prior structures are eliminated, by providing afabric composed either entirely or in part of continuous laminatefilaments (advantageously between about 0.5 and percent of the laminatefilaments with any remainder being any commonly employed natural orman-made fiber), each laminate filament having (A) at least onepolymeric ply bonded to (B) a ply made of electrically conductivematerial and having at least one discontinuity along its length. Thestructure is fabricated using standard weaving, knitting, netting,tufting, or braiding techniques.

Although it is necessary to produce only one discontinuity along thelength of the electrically conductive ply of each laminate filament tobe utilized in fabricating the structure of the present invention, morethan one such discontinuity may be employed-if desired for any reason,or if naturally resulting fromthe process used to effectdiscontinuity--without any substantial vitlation of the antistaticproperties of the fabric, and without any substantial furtherenhancement in the disposition of the electrocution hazard. Indeed, whenmany discontinuities are present in the otherwise electricallyconductive ply of the laminate filament, e.g., when the average intervalbetween discontinuities is as small as approximately one inch, theantistatic properties of the fabric have been found to be satisfactory.No technical advantage is presently envisioned, however, in theproduction of such or larger numbers of discontinuities.

In fine, the instant invention comprehends in essence the interruptionof the continuum of conducting surface which would have been establishedunder the prior art for the purpose of dissipation of static electricitygenerated in the fabric, one interruption along the length of theelectrically conductive ply of each laminate filament employed in thestructure being necessary to dispose of the electrocution hazardotherwise presented, more than one such interruption (and even verymany) being acceptable, although not especially advantageous. That anysuch interruption would not cause an enormous diminution in thedissipation of static electricity generated in the structure is totallyunexpected.

- invention, including its objects and benefits, reference is made tothe detailed description set forth below, which should be read togetherwith the accompanying drawing, wherein:

FIG. 1 is a plan view of one preferred fabric in accordance with theinvention;

FIG. 2 is a warpwise section of another ric embodying the invention;

FIG. 3 is a perspective view of one preferred form of novel, continuouslaminate filament employed in the fabrics of FIGS. 1 and 2; and

FIG. 4 is a sectional view of the laminate filament of FIG. 3.

preferred fab- DESCRIPTION OF THE PREFERRED EMBODIMENTS With particularreference to the drawing, FIG. 1 shows a woven fabric according to theinvention, produced by interweaving laminate filaments (30) withordinary threads (11) which are made from natural fibers such as cottonor wool, and/or man-made fibers such as nylon, rayon, acrylic, orpolyester. The laminate filaments (30) are present in an amount equal toabout 0.5-100 percent by weight of the woven fabric (10).

Referring now to FIG. 2, there is shown a pile fabric according to theinvention, which fabric comprises a backing material (21) having pileloops (22) anchored to the backing material (21). In the picturedembodiment, the backing material (21) comprises chain yarns (23)interwoven with filler yarns (24), as is well known in the art. Thebacking material may possess any other structure heretofore employed inthe production of pile fabrics. The backing material (21) may beconstructed from any of the materials commonly employed in the art, suchas jute or hemp, among many others. The pile loops (22) comprise a yarn(25), which is made of one or more strands, three such strands beingpictured here. The yarn (25) contains a laminate filament which ispresent in an amount equal to about 0.5-100 and preferably 2-l5 percentby weight of the yarn (25). The balance, if any, of the yarn (25)comprises any commonly employed natural or man-made fibers (26).

Laminate filaments according to the present invention may be preparedfrom any of the well-known film or fiber forming polymers, such ascellulosics, polyamides, polyolefins or polyesters coated with a layeror laminated to a ply made of an electrically conductive material. Thiselectrically conductive material is preferably a metal or mixture ofmetals and most preferably, for laminate filaments prepared by theslitting of laminated films, consists of a metal foil. Equallysatisfactory conductive plies can be prepared by plating films orfilaments with metal, for example, electrolytically or by high vacuumdeposition methods so long as such metal deposits are thick enough toprovide adequate electrical conductivity. Vapor deposited aluminumcoatings must, for example, be about 0.5 microns in thickness to obtainadequate electrical conductivity. such conductive plies must, of course,be adequately adherent to withstand textile processing and userequirements. This is readily accomplished by lamination ofa secondpolymeric ply over the electrically conductive ply. Satisfactory resultscan also be obtained by coating the metallic ply with polymers oradhesives, which in some cases may require curing. Moreover, suchcoatings can contain finely divided metal particles and/or otherelectrically conductive materials, thus directly providing the requiredelectrically conductive ply.

Turning now to FIGS. 3 and 4, there is shown a preferred laminatefilament (30) which is used in the construction of the fabrics (10 and(20) pictured in FIGS. 1 and 2. This laminate filament (30) is amodification of those already known in the art, as, for example, thoseshown in Scharf, US. Pat. No. 3,069,746. The laminate filament (30)comprises a metal ply (33) bonded on each side thereof to polymericplies (31) and (32) by suitable means, such as layers of adhesive (34)and 35). The metal ply (33) may be composed of copper, silver, nickel,chromium, lead, tin, or aluminum, or' alloys of these metals. Aluminumis preferred because of its properties of high ductility, electricalconductivity, and resistance to oxidative changes. The polymeric plies(31) and (32), which may be composed of the same or different materials,are prepared from any of many well-known polymeric materials. Preferredpolymeric materials are the fiber-forming polymers having a high tensilestrength, such as the cellulosics, e.g., cellulose butyrate; thepolyamides, e.g., nylon; the polyolefins, e.g., crystallinepolypropylene; and most preferably, the polyesters, e.g., polyethyleneterephthalate.

The laminate filament (30) is further characterized by the presence ofat least one interruption or discontinuity (36) along the length of themetal ply (33). The mean distance between segments of continuous metalply, i.e., the mean length of the discontinuity (36), is at least about0.003 inches, such being ordinarily sufficient to eliminate coronadischarge at potentials readily available from convenience outlets. Morethan one discontinuity (36) may be present along the length of the metalply (33) of the laminate filament (30), although such in neitherrequired nor particularly advantageous. Pictured in FIGS. 3 and 4 aretwo such discontinuities (36), which are schematically depicted here,solely for the purposes of simplicity, as regular voids resulting fromsharp, even breaks in the metal ply. That these voids are oftentimesirregular will be apparent to one skilled in the art, upon perusing theremaining portions of the disclosure.

In the incorporation of the laminate filaments of the present inventioninto pile fabrics, especially carpets, it has been found advantageous torecognize a relationship existing between the average distance betweensuccessive discontinuities in the metal ply of a particular laminatefilament--hereinafter designated L--and the average length of theindividual discontinuities therein--hereinafter designated G.Specifically, it has been found that loop pile carpets exhibiting highlysatisfactory static dissipation characteristics and presenting noappreciable electrocution hazard will result from the employment ofmetallic laminate filaments according to the present invention, whichfilaments have an L/G ratio equal to or greater than about I00.

As will be understood by one of skill in the art upon a careful readingof the foregoing portions of this detailed description, it is notnecessary that every end of yarn in the pile contain a strand of themetallic laminate filament. Moreover, more than one strand of metalliclaminate filament per end of yarn in the pile may be advantageous,especially under conditions of very low relative humidity.

The laminate filament (30) according to the present invention can have awidth of from less than 0.001 inches to over 0.25 inches, althoughwidths within this range are generally preferred, and a width of 0.01inches has been found suitable for a number of applications. Dependingupon such factors as the width of the filament (30), the thickness ofthe plies (31 (32), and (33), and the amount of adhesive (34) and 35), alaminate filament (30) useful in the present invention has a wide rangeof acceptable deniers.

Laminate filaments (30) employed in preparing the fabric of thisinvention are conveniently prepared by modifications of standardprocesses known in the art for the production of ordinary laminatefilaments, such, for example, as is shown in Scharf US. Pat. No.3,069,746. By way of example, to produce laminate filaments (30), usedin this invention, a discontinuous adhesive layer is applied to one orboth of the opposed surfaces of webs of the selected polymeric film andmetal foil, which materials are then laminated into a 3-ply structure bymeans of heat and pressure, for example, in a continuous manner,utilizing pairs of pressure rollers adapted to bring the webs intointimate contact. The resulting laminate is then stretched to a degreesufficient to break the metallic layer at the point(s) at which noadhesive is present, but insufficient to break the metallic layer in therelatively greater areas where adhesive, film, and foil are in intimatecontact. After being so stretched, the laminate is then slit into narrowstrands of the desired width. Alternatively, the laminate may be firstslit into narrow strands, which strands are then stretched to thedesired degree.

The present invention may be better understood by a reference to thefollowing illustrative examples, wherein all parts and percentages areby weight unless otherwise indicated.

EXAMPLE I This example specifies detail concerning the structure andcharacteristics of certain of the laminate filaments embodying thepresent invention.

A 3-ply laminate was prepared from two sheets of polyethyleneterephthalate, each of which was about 0.0005 inches in thickness, and asheet of aluminum 0.00045 inches in thickness, employing a commerciallyavailable polyester adhesive to bond the polyethylene terephthalatesheets to each side of the aluminum sheet. Before the lamination waseffected, however, a wedge-shaped area had been removed from thealuminum sheet, with the result that when the laminate was subsequentlyslit into specimens 0.01 inches in width, a series of laminate filamentswas obtained, each having a single discontinuity in the metal plythereof, the length of this discontinuity or gap" varying from 0 toabout 0.100 inches.

A. Employing a current measuring cell equippedwith salt water contactsand utilizing a source of essentially unlimited electrical current, eachfilament of the series prepared as described above was individuallytested to determine whether it would conduct an electrical cur rent at apotential of 440 volts rms (60 HZ). Those filaments having a length ofdiscontinuity or gap in the metal ply of 0.003 inches or more conductedno measurable current under these circumstances.

B. ln a second set of tests performed upon the series of filamentsdescribed above, the minimum potential necessary for each filament toconduct an electrical direct current was determined. The results of thisseries of tests are summarized in the accompanying Table I.

TABLE I Length of discon- Minimum potential necessary TABLE l-ContinuedLength of discon- Minimum potential necessary Illustrated in thisexample is a useful method of construction of a laminate filamentaccording to the present invention. A sheet of aluminum 0.00045 inchesthick was laminated to two sheets of polyethylene terephthalate, each ofwhich was 0.0005 inches thick, employing a commercially availablepolyester adhesive on each side of the aluminum. Instead of the twocontinuous layers of adhesive, as is generally employed in the art--see,e.g., US. Pat. No. 3,069,746 a discontinuous adhesive layer was appliedto one side of the aluminum, each of the discontinuities in the adhesivelayer being approximately 1/16 inch in length, and the average intervalbetween the discontinuities being approximately 32 inches, thesedistances being measured along the linear direction of the laminate.After the adhesive had been cured, the laminate was slit into filamentsabout 1/ inch wide, which filaments were then stretched to about 40percent of their original length. Under such conditions, it was observedthat the metallic foil component of the laminate was broken intodiscontinuities of approximately l/l 6 inch in length, the averagelength between discontinuities being about 32 inches, both measurementsbeing taken along the length of the filament. It was also observed thatthe polymeric components of the laminate remained intact, nodiscontinuities being observable therein. This filament, which isdesignated Filament A, had a denier of about I50.

EXAMPLE 3 Illustrated in this example are structures of other laminatefilaments according to the present invention. Employing a procedureequivalent to that outlined in Example 2 above, metallic laminatefilaments, otherwise identical to those in Example 2 above, wereprepared having the following characteristics:

For comparative purposes, a metallic laminate filament otherwiseidentical to those of Examples 2 and 3 above, but having nodiscontinuities in the metal ply thereof, was prepared using standardtechniques, as, for example, according to US. Pat. No. 3,069,746. Thisfilament, which is not useful in the practice of the present invention.is designated Filament I, being prepared for comparative purposes only.

EXAMPLE This example illustrates the production of a composite yarnuseful in the practice of the present invention. A single strand of themetallic laminate Filament A of Example 2 above was twisted with twoends of 2/ l cotton count yarn of polymerized acrylonitrile.

The resulting yarn contained 3 weight percent of the metallic laminatefilament, based upon the weight of the yarn. This yarn is designatedYarn A.

EXAMPLE 6 Using the procedure of Example 5, Filaments B, C, D, E, F, G,and H were individually employed in the preparation of seven othercomposite yarns useful in the preparation of a fabric in accordance withthis invention, which yarns are designated as follows:

Filament Yarn B B C C D D E E F F G G H H EXAMPLE 7 This example, whichis not illustrative of the present invention, is set forth forcomparative purposes only. Using the procedure of Example 5, Filament lof Example 4 was employed in the preparation of a composite yarn whichis not useful in the preparation of a fabric in accordance with thisinvention, such yarn being designated Yarn l.

EXAMPLE 8 This example, which is also not illustrative of the presentinvention, is set forth for comparative purposes only. Two ends of 2/ lcotton count yarn of polymerized acrylonitrile and containing nometallic laminate filament were twisted together. The resulting yarn isdesignated Yarn J.

EXAMPLE 9 STATIC ELECTRICITY TEST The fabric to be tested is first cutinto sample squares 36 inches on a side. These samples are conditionedfor 7 days by being hung from racks in a test room equipped with arubber floor mat and having an area of at least 100 square feet, whereinthe temperature is controlled at 70i 2F. and the relative humidity iscontrolled at percent i 1 percent. Free circulation of air over allsample surfaces is effected, but the samples are not allowed to contacteach other. A pair of leathersole test shoes is also conditioned for thesame period, under the same conditions.

Residual static change on the rubber floor mat is then neutralized bypassing twice over its entire surface a polonium wand, which consists of6 polonium 210 alloy strips mounted end-to-end on a head attached to ahandie. A fabric sample is then placed upon the rubber floor mat, andits residual static charge is neutralized in the same manner. Theleather soles of the test shoes are then cleaned by sanding their entiresurface with fine sandpaper, followed by a wiping with cheesecloth toremove dust particles.

Wearing the test shoes and holding a hand probe which is connected to anelectrostatic detection head, a human operator steps upon the carpetsample and grounds the probe. Then while holding the hand probe, theoperator walks normally on the sample at a rate of 2 steps a second fora 30-second period, being careful not to scuff or rub the shoes over thefabric. if at the end of the 30-second period the voltage has notreached a steady maximum, the walk is continued for an additional 30seconds. The maximum voltage recorded during the walk is the staticlevel of the sample, the average for two operators being recorded inTable II as static electricity in volts. Other standard tests are usedfor determining the static level of fabrics having utility as garments,etc.

CONDUCTIVITY TEST The test for electrical conductivity was performed inaccordance with Number 56 of the National Fire Protection AssociationStandards, revision of June 1968, entitled Code for the Use of FlammableAnesthetics 1968, available from the National Fire protectionAssociation, 6O Batterymarch Street, Boston, Mass. 021 10. To meet therequirements of this Code, a conductive fabric used as a floor coveringshall have a resistance of greater than 25,000 ohms, as measured betweena ground connection and an electrode placed at any point on the floorcovering, and also as measured between 2 electrodes placed 3 feet apartat any points on the floor covering.

The fabric to be tested is first cleaned and dried, and the test roomfreed of any flammable gas mixtures. Provided are 2 electrodes, eachweighing 5 pounds and having a dry, flat, circular contact area 2 /2inches in diameter, which comprises a surface of aluminum foil about0.001 inch thick, backed by a layer of rubber inch thick and measuringbetween 40 and 60 durometer hardness as determined with a Shore Type Adurometer. (See American Society for Testing and Materials Methoddesignated D-2240-64T, obtainable from the Society at 1916 Race Street,Philadelphia, Pa. 19103.) Provided also are two lead wires and acalibrated ohmmeter which operates on a nominal open circuit outputvoltage of 500 volts DC. and a shortcircuit current of 2.5 to 10milliamperes, the scale of the ohmmeter showing units of resistance.

Measurements of the resistance of the fabric are made at five or morelocations on the floor covering,

and the results are averaged. If the resistance changes appreciably withtime during a measurement, the value observed after the voltage has beenapplied for about 5 seconds is considered the measured value. Whereresistance to ground is measured, two measurements are appended claims.

What is claimed is: l. A continuous laminate filament which comprises:

A. A polymeric ply bonded to V g B. A ply made of electricallyconductive material and havinga discontinuity along its length. 2. Alaminate filament according to claim 1, wherein the electricallyconductive material is a metal.

3. A fabric comprising a continuous laminate fila- TABLE II Mean lengthin inches of Mean distance in inches Designation of Weight percentdiscontinuities in between discontinuities Static Fabric the yarn in theof metallic laminate I the metal ply of the in the metal ply of L/GElectricity Resistance pile fabric filament in the yarn metalliclaminate the metallic laminate volts ohms Filament employed (G) filamentemployed (L) THIS INVENTION 3 0.06 32 533 1400 13 3 0.003 I 333 3250 10C 3 0.003 10 3333 2750 10 D 3 0.003 100 33333 2250 10 E 3 0.02 10 5002900 10 F 3 0.02 100 5000 2250 10 G 3 0.1 10 100 3400 10 H 3 0| 100 10002400 10 FOR COMPARISON s i I (no discontinuities) (no discontinuities) w2000 10 J 0 I 2000 107 From Table I it can be seen that although thepassage of current from an ordinary electrical outlet is effectivelyblocked by discontinuities of at least 0.003 inches in the metal ply ofa laminate filament according to the present invention as evidenced bythe resistance being much greater than 25,000 ohms, such discontinuitiesare not capable of preventing the dissipation of the charges of muchgreater magnitude which might result. for example, from repeated rubbingand separation of shoes and carpet pile.

From Table II it can be seen that pile fabrics according to the presentinvention. when employed as carpets in anatmosphere the'relativehumidity of which is percent, will not generate a static charge aboveabout 3,500 volts, which is in proximity to the threshold level of humansensitivity. From Table ll it can also be seen that the same fabrics donot present an electrocution hazard, as evidenced by the resistancedata. Furthermore, it can be seen from Table II that a pile fabricaccording to the present invention possesses this highly desirablecombination of properties when the laminate filaments comprising it havean L/G ratio, as hereinbefore explained, of at least about 100.

Fabrics having this combination of properties find special utility notonly as carpets, rugs, and other floor coverings, but also as bedcoverings, especially in hospitals', as curtains, especially inhospitals for separation of cubicles; and in the production of articlesof clothmg.

Although the present invention has been described in detail with respectto certain preferred embodiments thereof, it is apparent to those ofskill in the art that variations and modifications in this detail may beeffected without any departure from the spirit and scope of the presentinvention, as defined in the heretoment, which comprisesf A. A polymericply bonded to B. A ply made of electrically conductive material andhaving a discontinuity along its length.

4. A fabric according to claim 3, wherein the electrically conductivematerial is a metal.

5. A pile fabric comprising:

A. A backing material; and

B. Pile anchored in the backing material, the pile comprising acontinuous laminate filament, which comprises: i

l. A metal ply having at least one discontinuity of at least about 0.003inches along the length thereof, and

2. A polymeric ply bonded to the metal ply; the

ratio of the mean distance between discontinuities in the metal ply tothe mean length of the discontinuities being at least about 100.

6. A pile fabric according to claim 5, wherein the metal ply is aluminumand the polymeric ply is polyeth

1. A CONTINUOUS LAMINATE FILAMENT WHICH COMPRISES: A. A POLYMERIC PLYBONDED TO B. A PLY MADE OF ELECTRICALLY CONDUCTIVE MATERIAL AND HAVING ADISCONTINUITY ALONG ITS LENGTH.
 2. A laminate filament according toclaim 1, wherein the electrically conductive material is a metal.
 2. Apolymeric ply bonded to the metal ply; the ratio of the mean distancebetween discontinuities in the metal ply to the mean length of thediscontinuities being at least about
 100. 2. Two polyethyleneterephthalate plies, the polyethylene terephthalate plies being bondedto opposite sides of the aluminum ply; the ratio of the mean distancebetween discontinuities in the aluminum ply to the mean length of thediscontinuities being at least about
 100. 3. A fabric comprising acontinuous laminate filament, which comprises: A. A polymeric ply bondedto B. A ply made of electrically conductive material and having adiscontinuity along its length.
 4. A fabric according to claim 3,wherein the electrically conductive material is a metal.
 5. A pilefabric comprising: A. A backing material; and B. Pile anchored in thebacking material, the pile comprising a continuous laminate filament,which comprises:
 6. A pile fabric according to claim 5, wherein themetal ply is aluminum and the polymeric ply is polyethyleneterephthalate.
 7. An antistatic carpet comprising: A. A backingmaterial; B. Pile anchored in the backing material, the pile comprisinga continuous laminate filament, which comprises: